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Monomelic Amyotrophy

Hirayama Disease


  • CASE PRESENTATION: A 28-year-old white man presented with insidious-onset, slowly progressive, unilateral weakness and atrophy of his left shoulder girdle and deltoid muscles.[ncbi.nlm.nih.gov]
  • Abstract Pediatric monomelic amyotrophy may present a diagnostic challenge. This is particularly true for immigrant or adopted children who have little or no available medical history.[ncbi.nlm.nih.gov]
  • Clinical profile, imaging and electrophysiological findings of the patient aged 50 years will be described in detail as presentation at this age is exceptional. Collar therapy slowed progression in most cases.[ncbi.nlm.nih.gov]
  • Abstract Monomelic amyotrophy is a sporadic juvenile-onset disease that presents with gradual onset of weakness and atrophy in the hand muscles unilaterally.[ncbi.nlm.nih.gov]
  • Abstract A 30-year-old patient of Central European origin, suffering from monomelic amyotrophy, is presented. The disease was characterized by proximal weakness of one upper limb, mainly of the shoulder girdle, accompanied by atrophy.[ncbi.nlm.nih.gov]
  • A total of 190 patients were diagnosed to have MMA in our institute over the last 27 years and this is the first case of familial MMA.[ncbi.nlm.nih.gov]
  • In conclusion, a large cohort of patients with monomelic amyotrophy seen over 35 years (1976-2010) is described.[ncbi.nlm.nih.gov]
  • In conclusion, a large cohort of patients with monomelic amyotrophy seen over 35 years (1976–2010) is described.[doi.org]
  • Abstract A male Caucasian patient is presented with a greater than 10-year history of painless weakness of the right leg, stable over the last 7 years. His examination demonstrated severe wasting and moderate weakness of his right calf muscle.[ncbi.nlm.nih.gov]
  • OBJECTIVES: The objective of our study was to describe the clinical characteristics, electrophysiology, MRI features and conduct viral assays in patients with Monomelic Amyotrophy (MMA) and follow them up over one year.[ncbi.nlm.nih.gov]
  • METHODS: Cortical excitability studies were prospectively performed in 8 monomelic amyotrophy patients and compared to 21 early-onset amyotrophic lateral sclerosis (ALS) patients and 40 healthy controls.[ncbi.nlm.nih.gov]
  • Well-written 4.0 1 rating Dear Reader, We are very excited about New Features in JOCR. Please do let us know what you think by Clicking on the Sliding “Feedback Form” button on the[jocr.co.in]
  • Altered axonal excitability properties in juvenile muscular atrophy of distal upper extremity (Hirayama disease). Clin Neurophysiol. 2011;122:205–209. 10. Zhou B, Chen L, Fan D, Zhou D. Clinical features of Hirayama disease in mainland China.[dovepress.com]


  • treatment is recommended for eligible patients because of its lower associated risks.[ncbi.nlm.nih.gov]
  • The purpose of this study was to examine the outcomes of patients with cervical flexion myelopathy who received surgical treatment. A retrospective study was conducted.[ncbi.nlm.nih.gov]
  • Management and treatment There is no cure for MA. Treatment is conservative and with early detection aims to slow the progression of muscle wasting.[orpha.net]
  • The purpose of this study was to examine the outcomes of patients with cervical flexion myelopathy who received surgical treatment. Methods A retrospective study was conducted.[doi.org]
  • Other treatment options include muscle strengthening exercises and therapies to improve hand coordination. [1] Surgery for the treatment of MMA is debated, as there are benefits and risks associated with surgery. [5] People who are diagnosed with MMA[rarediseases.info.nih.gov]


  • The disease, which is probably of the anterior horn cells, had a benign course and good prognosis, as evident from repeated examinations during a follow-up of eight years.[ncbi.nlm.nih.gov]
  • […] diagnosis with other motor neuron diseases, the history of an amyotrophy clinically localized for more than 3 years to a lower single limb and the characteristic muscular CT pattern suggest the diagnosis since the first observation and indicate a favorable prognosis[ncbi.nlm.nih.gov]
  • Their clinical features, electrophysiology, imaging, muscle biopsy and laboratory tests, treatments, and prognosis were analysed. We compared the results with data from other countries or regions. The mean age at onset was 16.8 years.[ncbi.nlm.nih.gov]
  • There is a need to lump all the nomenclatures under the rubric of HD as prognosis in this condition is benign and prompt diagnosis is important to institute early collar therapy.[ncbi.nlm.nih.gov]


  • Etiology The exact etiology is unknown.[orpha.net]
  • Axial magnetic resonance imaging demonstrated signal changes of "snake-eye" appearance in the cervical anterior horn region, similar to ischemic myelopathies caused by various etiologies.[ncbi.nlm.nih.gov]
  • BACKGROUND: Monomelic amyotrophy (MMA) is a benign motor neuron disorder, which particularly affects young people and the etiology is still unknown. Gangliosides are located on the outer surface of motor neurons.[ncbi.nlm.nih.gov]
  • The author proposes that the etiology of this disease is disproportionate growth between the vertebral column and the contents of the spinal canal especially the dural sac during the juvenile growth.[ncbi.nlm.nih.gov]
  • Commentary Blessedly few MA patients come to autopsy, but one such patient demonstrated ischemic changes in C5 to T1 anterior horn cells supporting a vascular etiology ( J Neurol Neurosurg Psychiatry 1987;50:285-290).[ahcmedia.com]


  • The nationwide epidemiological study in Japan was carried out from 1996 to 1998, identified 333 cases of the disease. There were fewer case reports from other countries than from Japan.[ncbi.nlm.nih.gov]
  • Divided into four sections, the text begins with an introduction to tropical diseases of the central nervous system, and their epidemiology.[books.google.com]
  • Each chapter begins with a shot historical account of the disease, followed by a critical evaluation of the epidemiological and/or hospital based data. This is then compared with the data of other global populations.[books.google.com]
  • Summary Epidemiology The prevalence is unknown. It is seen mainly in Asian countries (particularly in Japan and India) with only a very few cases reported in Europe and the United States.[orpha.net]
  • CONCLUSIONS: This case of Hirayama disease is peculiar due to its epidemiological characteristics and is presented here with the aim of making this entity more widely known in our milieu.[ncbi.nlm.nih.gov]
Sex distribution
Age distribution


  • We call attention to this rare location of MA, as well as describe some theories concerning its pathophysiology .[ncbi.nlm.nih.gov]
  • The good result obtained in our case suggests that an excessive range of flexion of the cervical spine might play a key role in the pathophysiology of the disease. Thus, a simple and safe anterior fusion procedure could be the best choice.[doi.org]
  • The pathophysiology of MA remains unknown [ 4 ], but several postulations have been considered, such as viral infections, ischemia to anterior horn cells, and atopy [ 6, 9 ].[jmedicalcasereports.biomedcentral.com]
  • Pathophysiology This is a degenerative condition that affects motor neurons, namely the anterior horn cells of the spinal cord and the motor cranial nuclei.[patient.info]
  • Clinical and pathophysiological concepts of neuralgic amyotrophy. Nat Rev Neurol. 2011 May 10. 7(6):315-22. [Medline]. van Alfen N, van Engelen BG, Hughes RA. Treatment for idiopathic and hereditary neuralgic amyotrophy (brachial neuritis).[emedicine.medscape.com]


  • As a second-line alternative to cervical collar treatment, surgical anterior cervical decompression and fusion via DDF or CDF may prevent further deterioration and produce good short-term therapeutic effects in patients with MMA; however, cervical collar[ncbi.nlm.nih.gov]
  • But the big story for MS continues to be how to prevent progression. There is still not a single drug that prevents progression.[practicalneurology.com]
  • 1 Department of Neurosurgery, Taipei Medical University–Wan Fang Hospital; 2 Division of Neurosurgery, Department of Surgery, Taipei County Hospital; 3 Graduate Institute of Clinical Medicine, College of Medicine, and 5 Graduate Institute of Injury Prevention[doi.org]
  • Application of a cervical collar to minimize neck flexion prevents progressive muscular weakness in an early stage of the disease. (Internal Medicine 39: 283-290, 2000)[jstage.jst.go.jp]
  • A cervical collar worn in the early stages of disease has been shown to halt progress of the disease in some cases, as it prevents neck flexion. Muscle strengthening exercises and hand coordination training can also be helpful.[orpha.net]

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